Overweight in adolescence affects 30 percent of African-American girls and is an important target for preventive efforts because of its implications for lifelong increased health risk. We have assembled a multidisciplinary team of scientists from the Pennington Biomedical Research Center and from Louisiana State University to test the efficacy of an internet-based secondary prevention program for obesity in African-American adolescent girls who are overweight and at risk for chronic obesity. We will recruit families from rural areas of South Louisiana, which is an underserved population with very significant health problems. The project will test the hypothesis that a family- oriented behavioral internet-based intervention is more efficacious for weight loss than an internet-based nutrition education condition. Adolescent participants who are overweight and have at least one obese parent will be randomly assigned to one the of two experimental conditions. Both the behavioral intervention and the control condition will utilize the internet to provide health interventions which will span two years. The behavioral intervention will focus upon the promotion of healthy eating and exercise for weight management in the overweight adolescent girls and the obese parent. The primary endpoints for the study will be Body Mass Index, expressed as percentile for a particular age, and percent body fat, as measured by dual-energy absorptiometry. Secondary endpoints will measure a variety of health indicators and health behaviors. The project's major strength is its use of an innovative approach, an interactive internet program, to promote compliance. Internet interactions with the research team will be frequent, and will supplement less frequent face-to-face contact in therapy sessions. We hypothesize that the internet-based behavioral intervention will remove obstacles to treatment such as travel and significant time commitments by the family, thereby enhancing compliance with the behavioral prescriptions of the program. This program can be conceptualized as a secondary prevention program since adolescent participants will be overweight and the development of chronic obesity in adulthood may be circumvented if the behavioral internet-based intervention is successful. Furthermore, if this approach is successful, the technology lends itself to widespread implementation.